Various training methods for two way memory effect (TWME) and stressed two way memory effect (STWME) were tried on Cu 13.4Al 4.0Ni (mass fraction, %) single crystals by applying tensile stress along 〈001〉 direction ...Various training methods for two way memory effect (TWME) and stressed two way memory effect (STWME) were tried on Cu 13.4Al 4.0Ni (mass fraction, %) single crystals by applying tensile stress along 〈001〉 direction of β phase. The training method of cooling with load can induce a lot of martensite prone to stabilize, thus cause large residual deformation, wide hysteresis and small TWME. Training with constant load can produce STWME larger than 8% with the least residual deformation. By training procedure of martensite reorientation below M f followed by thermal cycling, the TWME is relatively large with very small residual deformation and with comparatively narrow hysteresis of two way memory. The obtained two way memory curve after such training is not a closed loop, and the obtained TWME is not stable. However, these can be improved by thermal cycling. Training with martensite reorientation below M f and thermal cycling under relatively low constant stress throughout the whole training procedure is the optimum way of obtaining TWME, and more than 1.7% TWME can be obtained. The thermomechanical history of the sample has a pronounced effect on the training result. Thermomechanical cycling has a softening effect on martensite. [展开更多
Effect of solution treatment temperature on transformations and two way memory, effect in a Ti- 55.2 wt-%Ni alloy was investigated. The results show that with increasing the solution treatment temperature (T_s), two w...Effect of solution treatment temperature on transformations and two way memory, effect in a Ti- 55.2 wt-%Ni alloy was investigated. The results show that with increasing the solution treatment temperature (T_s), two way memory effect (TWME) decreases continuously and temperatures of martensite and reverse, martensite transformations (MR) rise, but the temperature of R start trans- formation (parent→R) does not change. The results of the internal friction measurements indicate that when T_s=1073 K, internal friction peaks of MR and P→R transformations are larger than those of the specimens after solution-treatments at 973 and 1173 K. With increasing T_s, the de- crease of TWME can be attributed to that the defect stress field caused by the rolling fades out grad- ually and preferential martensite variants, which fit into the defect stress field, decrease. The changes of transformation temperatures and internal friction peaks with T_s are closely related to the change of defect numbers.展开更多
The snap-acting transition and two way shape memory (TWSM) effect have been obtained in a TWSM spring made of Ni51Ti49 alloy using the constrained effect of stress on driving force of TWSM material.When the snap-actin...The snap-acting transition and two way shape memory (TWSM) effect have been obtained in a TWSM spring made of Ni51Ti49 alloy using the constrained effect of stress on driving force of TWSM material.When the snap-acting transition has been realized:M_s= M_f and A_s=A_f;hysteresis is rectangular,the height (TWSM effect) and width (hysteresis) of the rectangle can be readjusted by means of constrained stress.The results of resistance measurments show that,the snap-acting TWSM effect mentioned above was supplied mainly from the transformation of P←→R.The thermodynamic model has also been proposed to ac- count for the snap-acting transformation.展开更多
In this paper, we extend the works by [1-5] accounting for autocorrelation both in the time specific effect as well as the remainder error term. Several transformations are proposed to circumvent the double autocorrel...In this paper, we extend the works by [1-5] accounting for autocorrelation both in the time specific effect as well as the remainder error term. Several transformations are proposed to circumvent the double autocorrelation problem in some specific cases. Estimation procedures are then derived.展开更多
For the three-dimensional nonlinear two-phase displacement problem, the modified upwind finite difference fractional steps schenles were put forward. Some techniques, such as calculus of variations, induction hypothes...For the three-dimensional nonlinear two-phase displacement problem, the modified upwind finite difference fractional steps schenles were put forward. Some techniques, such as calculus of variations, induction hypothesis, decomposition of high order difference operators, the theory of prior estimates and techniques were used. Optimal order estimates were derived for the error in the approximation solution. These methods have been successfully used to predict the consequences of seawater intrusion and protection projects.展开更多
Aesthetic education and ideological and political education undertake the educational responsibilities of educating people with beauty and cultivating people with morals,respectively.The innovation of aesthetic educat...Aesthetic education and ideological and political education undertake the educational responsibilities of educating people with beauty and cultivating people with morals,respectively.The innovation of aesthetic education and the reform of ideological and political education have common educational goals and target students.Integrating aesthetic education with ideological and political education can promote the overall healthy development of students,which has both historical and practical significance.In this paper,the importance and characteristics of integrating aesthetic education with ideological and political education in colleges and universities are analyzed from multiple dimensions,and four feasible ways of integrating aesthetic education with ideological and political education are proposed.The latter draws on extracurricular activities,emotional touch,a pleasant aesthetic atmosphere,and educational synergy to improve students’aesthetic literacy and cultivate correct ideological and political concepts among students.A survey of 1,047 students showed that the understanding and acceptance of ideological and political education were strengthened and improved after implementing these innovative integration ways.Taken together,the exploration and practice of these integration ways contribute to expanding the effect of ideological and political education in the new era and constitute important parts of the reform of college and university education in the new journey.展开更多
文摘Various training methods for two way memory effect (TWME) and stressed two way memory effect (STWME) were tried on Cu 13.4Al 4.0Ni (mass fraction, %) single crystals by applying tensile stress along 〈001〉 direction of β phase. The training method of cooling with load can induce a lot of martensite prone to stabilize, thus cause large residual deformation, wide hysteresis and small TWME. Training with constant load can produce STWME larger than 8% with the least residual deformation. By training procedure of martensite reorientation below M f followed by thermal cycling, the TWME is relatively large with very small residual deformation and with comparatively narrow hysteresis of two way memory. The obtained two way memory curve after such training is not a closed loop, and the obtained TWME is not stable. However, these can be improved by thermal cycling. Training with martensite reorientation below M f and thermal cycling under relatively low constant stress throughout the whole training procedure is the optimum way of obtaining TWME, and more than 1.7% TWME can be obtained. The thermomechanical history of the sample has a pronounced effect on the training result. Thermomechanical cycling has a softening effect on martensite. [
文摘Effect of solution treatment temperature on transformations and two way memory, effect in a Ti- 55.2 wt-%Ni alloy was investigated. The results show that with increasing the solution treatment temperature (T_s), two way memory effect (TWME) decreases continuously and temperatures of martensite and reverse, martensite transformations (MR) rise, but the temperature of R start trans- formation (parent→R) does not change. The results of the internal friction measurements indicate that when T_s=1073 K, internal friction peaks of MR and P→R transformations are larger than those of the specimens after solution-treatments at 973 and 1173 K. With increasing T_s, the de- crease of TWME can be attributed to that the defect stress field caused by the rolling fades out grad- ually and preferential martensite variants, which fit into the defect stress field, decrease. The changes of transformation temperatures and internal friction peaks with T_s are closely related to the change of defect numbers.
文摘The snap-acting transition and two way shape memory (TWSM) effect have been obtained in a TWSM spring made of Ni51Ti49 alloy using the constrained effect of stress on driving force of TWSM material.When the snap-acting transition has been realized:M_s= M_f and A_s=A_f;hysteresis is rectangular,the height (TWSM effect) and width (hysteresis) of the rectangle can be readjusted by means of constrained stress.The results of resistance measurments show that,the snap-acting TWSM effect mentioned above was supplied mainly from the transformation of P←→R.The thermodynamic model has also been proposed to ac- count for the snap-acting transformation.
文摘In this paper, we extend the works by [1-5] accounting for autocorrelation both in the time specific effect as well as the remainder error term. Several transformations are proposed to circumvent the double autocorrelation problem in some specific cases. Estimation procedures are then derived.
基金the Major State Basic Research Program of China(No.G1999032803)the National Tackling Key Problems Program(No.20050200069)+1 种基金the National Natural Sciences Foundation of China(Nos.10771124,10372052)the Ph.D.Program Foundation of Ministry of Education of China(No.20030422047)
文摘For the three-dimensional nonlinear two-phase displacement problem, the modified upwind finite difference fractional steps schenles were put forward. Some techniques, such as calculus of variations, induction hypothesis, decomposition of high order difference operators, the theory of prior estimates and techniques were used. Optimal order estimates were derived for the error in the approximation solution. These methods have been successfully used to predict the consequences of seawater intrusion and protection projects.
基金Research Projects from Xinxiang Municipal Social Science Circles Federation(SKL-2023-126 and SKL-2023-136).
文摘Aesthetic education and ideological and political education undertake the educational responsibilities of educating people with beauty and cultivating people with morals,respectively.The innovation of aesthetic education and the reform of ideological and political education have common educational goals and target students.Integrating aesthetic education with ideological and political education can promote the overall healthy development of students,which has both historical and practical significance.In this paper,the importance and characteristics of integrating aesthetic education with ideological and political education in colleges and universities are analyzed from multiple dimensions,and four feasible ways of integrating aesthetic education with ideological and political education are proposed.The latter draws on extracurricular activities,emotional touch,a pleasant aesthetic atmosphere,and educational synergy to improve students’aesthetic literacy and cultivate correct ideological and political concepts among students.A survey of 1,047 students showed that the understanding and acceptance of ideological and political education were strengthened and improved after implementing these innovative integration ways.Taken together,the exploration and practice of these integration ways contribute to expanding the effect of ideological and political education in the new era and constitute important parts of the reform of college and university education in the new journey.
